Fluid flow control of vacuum mounting

ABSTRACT

Systems and methods for mounting of material samples via a vacuum system and controlling fluid flow through a tube of the vacuum system are disclosed. In some examples, the vacuum system may be a castable and/or cold mounting vacuum system that facilitates mounting and/or encapsulation of material samples in epoxy resin under low, vacuum, and/or near vacuum pressure. In some examples, the vacuum system may comprise a flow control device configured to control epoxy flow through a dispensing tube that connects to a hollow vacuum chamber. In some examples, the vacuum chamber may have an opening defined by a rim sandwiched between upper and lower portions of a sealing ring. A movable lid may be configured to press down on the upper portion of the sealing ring when in a closed position, so as to seal the opening.

TECHNICAL FIELD

The present disclosure generally relates to vacuum systems and, moreparticularly, to fluid flow control of vacuum mounting systems.

BACKGROUND

Material testing systems measure the characteristics and/or behaviors ofmaterial specimens (e.g., metals, ceramics, plastics, etc.) undervarious conditions. Specimens that are brittle, cracked, porous, and/orotherwise sensitive may benefit from cold (also known as castable)mounting in an epoxy resin before testing. Cold mounting is a process ofspecimen encapsulation in an epoxy resin. Once mounted, the epoxy resincan aid in supporting porous or cracked features of material specimens.

Cold mounting vacuum systems pour an epoxy resin over a material samplein vacuum (or near vacuum) conditions. Conventionally, filling voids(e.g., pores and/or cracks) was difficult due to the air pressure withinthe voids. However, this difficulty is significantly reduced when avacuum (or near vacuum) is applied. The vacuum conditions help to removetrapped air from the voids. Subsequent curing at increased pressureswill force or push the resin into the voids. This process can enhancehelp retain and/or support delicate and/or friable material samples.

Limitations and disadvantages of conventional and traditional approacheswill become apparent to one of skill in the art, through comparison ofsuch systems with the present disclosure as set forth in the remainderof the present application with reference to the drawings.

SUMMARY

The present disclosure is directed to fluid flow control of vacuummounting systems, for example, substantially as illustrated by and/ordescribed in connection with at least one of the figures, and as setforth more completely in the claims.

These and other advantages, aspects and novel features of the presentdisclosure, as well as details of an illustrated example thereof, willbe more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a perspective view of an example vacuum system with a lidin a closed position, in accordance with aspects of this disclosure.

FIG. 1B shows another perspective view of the example vacuum system ofFIG. 1A with the lid in an open position, in accordance with aspects ofthis disclosure.

FIG. 2A shows a side view of the example vacuum system of FIG. 1A, inaccordance with aspects of this disclosure.

FIG. 2B shows a rear view of the example vacuum system of FIG. 1A, inaccordance with aspects of this disclosure.

FIG. 3A shows a bottom view of the example vacuum system of FIG. 1A,with a floor removed, in accordance with aspects of this disclosure.

FIG. 3B shows a cross section of the example vacuum system of FIG. 1A,about the line 3B-3B in FIG. 2B, in accordance with aspects of thisdisclosure.

FIG. 4A shows an enlarged portion of the cross section of FIG. 3B, withthe lid in an open position, in accordance with aspects of thisdisclosure.

FIG. 4B shows an enlarged portion of the cross section of FIG. 3B, withthe lid in a closed position, in accordance with aspects of thisdisclosure.

FIG. 5A shows a perspective view of an example flow control device ofthe example vacuum system of FIG. 1 in an extended position, inaccordance with aspects of this disclosure.

FIG. 5B shows a perspective view of the example flow control device ofFIG. 5A in a retracted position, in accordance with aspects of thisdisclosure.

FIG. 5C shows a perspective view of the example flow control device ofFIG. 5A in a retracted and rotated position, in accordance with aspectsof this disclosure.

FIG. 6A shows a top view of an example sheath of the example flowcontrol device of FIG. 5A, in accordance with aspects of thisdisclosure.

FIG. 6B shows a perspective view of the example sheath of FIG. 6A, inaccordance with aspects of this disclosure.

FIG. 6C shows a front view of the example sheath of FIG. 6A, inaccordance with aspects of this disclosure.

FIG. 7 shows a bottom exploded view of the example flow control deviceof FIG. 5A, in accordance with aspects of this disclosure.

FIGS. 8A-8C show side views of an example knob of the flow controldevice of FIG. 5A at different rotations, in accordance with aspects ofthis disclosure.

The figures are not necessarily to scale. Where appropriate, the same orsimilar reference numerals are used in the figures to refer to similaror identical elements.

DETAILED DESCRIPTION

Preferred examples of the present disclosure may be describedhereinbelow with reference to the accompanying drawings. In thefollowing description, well-known functions or constructions are notdescribed in detail because they may obscure the disclosure inunnecessary detail. For this disclosure, the following terms anddefinitions shall apply.

As used herein, the terms “about” and/or “approximately,” when used tomodify or describe a value (or range of values), position, orientation,and/or action, mean reasonably close to that value, range of values,position, orientation, and/or action. Thus, the examples describedherein are not limited to only the recited values, ranges of values,positions, orientations, and/or actions but rather should includereasonably workable deviations.

As used herein, “and/or” means any one or more of the items in the listjoined by “and/or”. As an example, “x and/or y” means any element of thethree-element set {(x), (y), (x, y)}. In other words, “x and/or y” means“one or both of x and y”. As another example, “x, y, and/or z” means anyelement of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z),(x, y, z)}. In other words, “x, y and/or z” means “one or more of x, yand z”.

As used herein, the terms “e.g.,” and “for example” set off lists of oneor more non-limiting examples, instances, or illustrations.

As used herein, the term “fluid,” when used as a noun, refers to afree-flowing deformable substance with no fixed shape, including, interalia, gas (e.g., air, atmosphere, etc.), liquid (e.g., water, solution,etc.), and/or plasma.

As used herein the terms “circuits” and “circuitry” refer to physicalelectronic components (i.e., hardware) and any software and/or firmware(“code”) which may configure the hardware, be executed by the hardware,and or otherwise be associated with the hardware. As used herein, forexample, a particular processor and memory may comprise a first“circuit” when executing a first one or more lines of code and maycomprise a second “circuit” when executing a second one or more lines ofcode. As utilized herein, circuitry is “operable” and/or “configured” toperform a function whenever the circuitry comprises the necessaryhardware and/or code (if any is necessary) to perform the function,regardless of whether performance of the function is disabled or enabled(e.g., by a user-configurable setting, factory trim, etc.).

As used herein, a control circuit and/or control circuitry may includedigital and/or analog circuitry, discrete and/or integrated circuitry,microprocessors, DSPs, etc., software, hardware and/or firmware, locatedon one or more boards, that form part or all of a control circuit,and/or are used to control a vacuum system.

Some examples of the present disclosure relate to a vacuum system formounting of material samples, comprising a flow control device,comprising a sheath having a central bore and a slot, and a dispensingknob received in the central bore of the sheath, the dispensing knobhaving a channel configured to receive a dispensing tube, wherein thedispensing knob is configured to move laterally between an extendedposition, where the channel is in alignment with the slot, and aretracted position, where the channel is out of alignment with the slot.

In some examples, the channel has a depth that varies based on arotatable position of the dispensing knob. In some examples, thedispensing knob is further configured to move between a first rotatableposition and a second rotatable position when the dispensing knob is inthe retracted position. In some examples, the depth of the channelproximate the slot is less in the second rotatable position than in thefirst rotatable position, such that fluid flow through the dispensingtube is more restricted in the second rotatable position than in thefirst rotatable position. In some examples, the system further comprisesa protrusion extending into the central bore, the protrusion beingreceived by a passageway of the dispensing knob. In some examples, thepassageway extends at least partially around a perimeter of thedispensing knob, thereby allowing the dispensing knob to rotate withinthe sheath. In some examples, the passageway comprises an arcuateportion extending at least partially around the perimeter of thedispensing knob and a lateral portion extending perpendicular to thearcuate portion. In some examples, the lateral portion of the passagewayslides over the protrusion when the dispensing knob moves laterallybetween the extended position and the retracted position. In someexamples, the arcuate portion of the passageway slides over theprotrusion when the dispensing knob moves between the first rotationalposition and the second rotational position. In some examples, thedispensing knob is prohibited from moving between the first rotatableposition and second rotatable position when the dispensing knob is inthe extended position.

Some examples of the present disclosure relate to a method ofcontrolling fluid flow through a tube of a vacuum system, the methodcomprising positioning the tube in a channel of a dispensing knob whilethe dispensing knob is in an extended position, the dispensing knobbeing retained within a sheath, and the channel being aligned with aslot of the sheath when the dispensing knob is in the extended position,moving the dispensing knob from the extended position to a retractedposition where the channel is out of alignment with the slot of thesheath, and rotating the dispensing knob while the dispensing knob is inthe retracted position, wherein the rotation causes the dispensing knoband sheath to pinch the tube.

In some examples, the channel has a depth that varies based on arotatable position of the dispensing knob. In some examples, rotatingthe dispensing knob comprises rotating the dispensing knob from a firstrotatable position to a second rotatable position. In some examples, thedispensing knob is prohibited from moving to the extended position fromthe retracted position when the dispensing knob is in the secondrotatable position. In some examples, the depth of the channel proximatethe slot is less in the second rotatable position than in the firstrotatable position, such that fluid flow through the tube is morerestricted in the second rotatable position than in the first rotatableposition. In some examples, the method further comprises rotating thedispensing knob from the second rotatable position to a third rotatableposition. In some examples, the depth of the channel proximate the slotis less in the third rotatable position than in the second rotatableposition, such that fluid flow through the tube is more restricted inthe third rotatable position than in the second rotatable position. Insome examples, a protrusion moves within a lateral passageway of thedispensing knob when moving the dispensing knob to the retractedposition. In some examples, a protrusion moves within an arcuatepassageway of the dispensing knob when rotating the dispensing knob. Insome examples, the method further comprises routing the tube from areservoir, through the channel of the dispensing knob, to a vacuumchamber of the vacuum system.

Some examples of the present disclosure relate to vacuum systems (e.g.,castable and/or cold mounting vacuum systems) that facilitate mountingand/or encapsulation of material samples in epoxy resin under low,vacuum, and/or near vacuum pressure. In some examples, a vacuum systemmay comprise a flow control device configured to control fluid (e.g.epoxy) flow through a dispensing tube. The dispensing tube may connectto a conduit that is sealingly fitted in a socket of a hollow vacuumchamber via a plug.

In some examples, the vacuum chamber may have an opening defined (atleast in part) by a rim sandwiched between upper and lower portions of asealing ring. A movable lid may be configured to press down on the upperportion of the sealing ring when in a closed position, so as to seal theopening. The vacuum chamber may additionally be in controllable fluidcommunication with a vacuum generator configured to adjust air pressurewithin the vacuum chamber, so as to create a low and/or near vacuumpressure environment. Control circuitry may be in electricalcommunication with valves that control whether the vacuum chamber is influid communication with the vacuum generator. The control circuitry maycontrol the valves (e.g., based on input received via a user interface)to allow the vacuum converter to (or prohibit the vacuum converter from)changing air pressure within the vacuum chamber.

FIGS. 1A-3B depict examples of a vacuum system 100. As shown, the vacuumsystem 100 includes a housing 102 and a vacuum chamber 104 positioned atleast partially within the housing 102. The housing 102 includes a frontpanel 106, side panels 108, a rear panel 110, a floor (not shown), and aceiling 112. In the examples of FIGS. 1A-2A, a user interface 114 isdisposed on the front panel 106. In some examples, the user interface114 may be a display screen having a touch screen interface. In someexamples, the user interface 114 may include buttons, knobs, speakers,microphones, levers, dials, keypads, and/or other input/output devices.The vacuum chamber 104 further includes an electrical connector 116 andcompressed air connector 118 on the rear panel 110 of the housing 102.In some examples, the compressed air connector 118 is configured forconnection to a source of compressed (or pressurized) air. In someexamples the electrical connector 116 is configured for connection withan electrical power source. The user interface 114 is in electricalcommunication with the electrical connector 116 on the rear panel 110 ofthe housing 102.

In the example of FIG. 1B, a reservoir 117 is positioned at leastpartially within a cavity formed in the ceiling 112 of the housing 102.As shown, a flow control device 500 and a pillar 120 are attached to theceiling 112 proximate the reservoir 117. The pillar 120 includes agroove 122 configured to fit a dispensing tube (not shown). The flowcontrol device 500 includes a channel 802 configured to receive thedispensing tube. As shown, a plug 124 having a conduit is furtherconfigured to receive an end of the dispensing tube, and bring thedispensing tube into fluid communication with a spout 126 within thevacuum chamber 104 (see, e.g., FIG. 3B). In some examples, the plug 124may comprise a collar formed of a hard plastic material, so as tofacilitate insertion into (and subsequent sealing of) a socket 125 ofthe vacuum chamber 104. In operation, pressure differential between theinside and outside of the vacuum chamber 104 may move epoxy resin fromthe reservoir 117 through the dispensing tube and into the vacuumchamber 104 via the spout 126. The flow control device 500 may controlthe flow of epoxy resin into the vacuum chamber 104 by pinching thedispensing tube to different degrees.

In the examples of FIGS. 1A-2B, the vacuum chamber 104 is largelydefined by a cylindrical sidewall 128. As shown, a rim 130 and sealingring 132 define an annular opening 134 of the vacuum chamber 104, alongwith sidewall 128. In some examples, the rim 130 may be part of sidewall128. In the example of FIG. 1A, the opening 134 of the vacuum chamber104 is covered by a lid 136. As shown, the lid 136 is substantially flatand circular. The lid 136 is hingedly attached to the sidewall 128 via amechanical linkage 138 (see also FIG. 2A). As shown, the hingedattachment comprises two hinges. This hinged coupling of the lid 136allows the lid 136 to move from the closed position of FIG. 1 to an openposition in FIG. 2.

As shown, with the lid 136 in an open position, the opening 134 of thevacuum chamber 104 is uncovered. When the lid 136 is in a closedposition (e.g., as shown in FIG. 1), the opening 134 is covered and thevacuum chamber 104 is substantially sealed by the arrangement of the lid136, rim 130, and sealing ring 132, without any outside intervention.The ability to maintain the seal without any outside interventionassists with ease of use of the vacuum system 100. For example, anoperator will not need to hold down the lid 136 before starting a vacuumcycle or between vacuum cycles. Additionally, the sealing arrangementrequires no oil, grease, or other lubricant, which saves time andreduces certain undesirable effects using of oil, grease, and/or otherlubricants. In operation, when a vacuum (or near vacuum) environment iscreated within the vacuum chamber 104, the lid 136 is pressed downfurther against the sealing ring 132 and rim 130, strengthening theseal.

FIGS. 3A-3B show internal views of the vacuum system 100. As shown, thevacuum system 100 includes a rotatable platform 140 positioned withinthe vacuum chamber 104. In some examples, the platform 140 may supportone or more containers 142, such as may receive epoxy via the spout 126.As shown, the rotatable platform 140 is configured for rotation via aspindle 144 that is in mechanical communication with a wheel actuator146 via a drive belt 148. In the examples of FIGS. 1A-3A, the wheelactuator 146 protrudes through an aperture in the side panel 108 of thehousing 102, so as to allow a user to easily rotate the platform 140during operation.

In the example of FIGS. 3A-3B, the interior of the vacuum chamber 104 isin fluid communication with a port 150. As shown, the port 150 ispositioned proximate a lower end and/or bottom of the vacuum chamber104. In the examples of FIGS. 3A-3B, the port 150 is in fluidcommunication with a first valve 153. The first valve 153 is also influid communication with a vacuum generator 152. In the example of FIGS.3A-3B, the vacuum generator 152 positioned within the housing 102. Insome examples, the vacuum generator 152 may instead be positionedoutside of the housing 102. In some examples the vacuum generator 152may comprise a vacuum converter. In some examples, the vacuum generator152 may comprise a pump. As shown, the vacuum generator 152 in fluidcommunication with a second valve 155. The second valve 155 is furtherin fluid communication with the air connector 118.

In the examples of FIGS. 3A-3B, the first valve 153 and second valve 155are in electrical communication with the control circuitry 154. In someexamples, the first valve 153 and/or second valve 155 may be solenoidvalves. In some examples, the control circuitry 154 may control thefirst valve 153 and/or second valve 155 to open and/or close in responseto one or more control signals received from the control circuitry 154.

In the example of FIG. 3A, the control circuitry 154 is in electricalcommunication with the user interface 114. In some examples, a user mayenter parameters of one or more vacuum cycles via the user interface114, and the parameters may be electrically communicated to the controlcircuitry 154. The control circuitry 154 may control the first valve 153and/or second valve 155 accordingly. In some examples, a user may selecta series of vacuum cycles via the user interface 114, as well asassociated properties of the series (e.g., number of vacuum cycles, timebetween each cycle, time of each cycle, pressure or vacuum level foreach cycle (e.g., −5 Megapascals), etc.), and the control circuitry 154may control the first valve 153 and/or second valve 155 to open and/orclose accordingly.

In some examples, the opening and/or closing of the first valve 153and/or second valve 155 may impact (e.g., raise and/or lower) pressurewithin the vacuum chamber 104. For example, the control circuitry 154may control the first valve 153 and second valve 155 (e.g., in responseto user input received via the user interface 114) to reduce pressure(and/or implement a given vacuum level) within the vacuum chamber 104.In the examples of FIGS. 3A-3B, when both the first valve 153 and secondvalve 155 are open, the vacuum generator 152 is in fluid communicationwith both the vacuum chamber 104 and the air connector 118. This mayallow the vacuum generator 152 to reduce pressure within the vacuumchamber 104 (e.g., using pressurized air provided via air connector118).

As another example, the control circuitry 154 may control the secondvalve 155 to close and the first valve 153 to remain open (e.g., inresponse to user input received via the user interface 114). In theexamples of FIGS. 3A-3B, when the first valve 153 is open and the secondvalve 155 is closed, the vacuum generator 152 is in fluid communicationwith the vacuum chamber 104, but not with the air connector 118. In someexamples, this arrangement may allow air pressure within the vacuumgenerator 152 to increase and/or equalize (e.g., via air available viavacuum generator 152).

As another example, the control circuitry 154 may control the firstvalve 153 to remain close, (e.g., in response to user input received viathe user interface 114) to maintain pressure within the vacuum chamber104. In the examples of FIGS. 3A-3B, when the first valve 153 is closed,the vacuum generator 152 is not in fluid communication with the vacuumchamber 104. This may restrict air pressure within the vacuum generator152 from changing, as fluid communication of the vacuum chamber 104 withanything outside the vacuum chamber 104 is restricted by the closedfirst valve 153.

In some examples, change in air pressure within the vacuum chamber 104may rely on (or at least be assisted by) the lid 136 being in a closedposition, with the lid 136 covering the opening 134. In examples wherethe air pressure is lowered, the resulting disparity in air pressure mayfurther force the lid 136 closed, increasing the strength of the sealformed by the lid 136. Conveniently, the sealing arrangement of the lid136, sidewalls 128, rim 130, and sealing ring 132 is sufficiently stableon its own. Thus, once the lid 136 is in the closed position, vacuumcycles may be started, stopped, and/or restarted with no need for anyexternal influence to maintain the seal.

In the examples of FIGS. 4A and 4B, the sealing arrangement of the lid136, sidewalls 128, rim 130, and sealing ring 132 can be seen in moredetail. As shown, an annular groove 156 is formed in the upper edge ofthe sidewall 128. The rim 130 overhangs a portion of the annular groove156. A lower portion 158 of the sealing ring 132 is positioned withinthe annular groove 156. As shown, the lower portion 158 of the sealingring 132 has a thickness has a lateral width that is approximately equalto that of the groove 156, and a height that is slightly greater thanthe distance between the floor of the groove 156 and the rim 130. Thisarrangement results in part of the lower portion 158 being compressedand/or pinched between the rim 130 and the sidewall 128 forming thefloor of the groove 156, thereby securing the sealing ring 132 in placevia a gripping frictional fit. In some examples, the rim 130 and/orsidewall 128 may be formed of a rigid material while the sealing ring132 is formed of a more pliable, compressible material (e.g., foam,rubber, etc.) so as to facilitate this arrangement.

In the examples of FIGS. 4A and 4B, the lower portion 158 of the sealingring 132 connects to an upper portion 160 of the sealing ring 132 at aliving hinge 162. As shown, the living hinge 162 is a flexible hingeformed of the same material as the sealing ring 132. As shown, thesealing ring 132 is cut or separated proximate the living hinge 162, soas to allow the upper portion 160 to move about the living hinge 162.

In the example of FIG. 4A, the lid 136 is in an open position, and theupper portion 160 of the sealing ring 132 extends upwards over and/oraway from the rim 130, into portions of the opening 134 that the lid 136would occupy in the closed position. In the example of FIG. 4B, the lid136 is in the closed position and pressing down on the sealing ring 132,thereby sandwiching the upper portion 160 of the sealing ring 132between the lid 136 and the rim 130. Being a pliable material, thesealing ring 132 is compressed between the lid 136 and the rim 130,allowing the lid 136 to come to its resting closed position, whilefilling any gaps between the lid 136 and the rim 130, so as to create asolid seal. In some examples, the lid 136 may be of a sufficient weightto compress the upper portion 160 of the sealing ring 132 with noadditional and/or outside assistance. Thus, vacuum cycles may bestarted, stopped, and restarted, with no need for an operator to holddown the lid 136 or make any adjustments. In operation, the sealingarrangement is further strengthened when air pressure is lowered withinthe vacuum chamber 104 (e.g., via the vacuum generator 152), whichfurther forces the lid 136 downward against the sealing ring 132 andtightens the seal. The sealing arrangement also needs no oil orlubricant to function correctly as some conventional seals require,which removes the need for repeated application of the oil/lubricantand/or other detrimental effects. Further, the sealing ring 132 acts asan intermediate buffer between lid 136 and rim 130, and lessens abrasionbetween the two.

In operation, once the vacuum chamber 104 is sealed, and pressure withinthe vacuum chamber is lowered, epoxy may be drawn into the vacuumchamber 104 from the reservoir 117 via the dispensing tube (not shown).FIGS. 5A-8C show examples of a flow control device 500 of the vacuumsystem 100 configured to control epoxy flow through the dispensing tube.In the examples of FIGS. 1A-1B, the flow control device 500 is attachedto the ceiling 112 of the housing 102 proximate the pillar 120. In theexamples of FIGS. 5A-5C, the flow control device 500 includes a knob 800fitted within a sheath 600.

In the examples of FIGS. 5A-8C, the knob 800 is configured to movebetween an extended position (such as shown, for example, in FIG. 5A)where a head 804 of the knob 800 extends away from the sheath 600, and aretracted position (such as shown, for example, in FIG. 5B), where thehead 804 of the knob 800 is flush against the sheath 600. As shown, theknob 800 includes a channel 802, and the sheath 600 includes a window602. The window 602 includes an arcuate slot 604 that substantiallyaligns with the channel 802 when the knob 800 is in the extendedposition of FIG. 5A. This alignment facilitates easy reception of thedispensing tube into (and/or removal of the dispensing tube from) thechannel 802 when the knob 800 is in the extended position.

In the example of FIG. 6B, the knob 800 is in the retracted position,and the arcuate slot 604 does not align with the channel 802. Thismisalignment makes it difficult to insert or remove the dispensing tubewhile the knob 800 is in the retracted position. Thus, the flow controldevice 500 can be put in the retracted position to secure the dispensingtube within the flow control device 500 and prevent removal. As shown,the window 602 further includes two parallel lateral slots 606 connectedby the arcuate slot 604. The lateral slots 606 align with the channel802 when the knob 800 is in both the extended and retracted positions.Thus, the lateral slots 606 allow the dispensing tube to extend into,out of, and/or through the flow control device 500 when the knob 800 isin both the retracted position and extended position.

FIGS. 6A-6C show further details of the sheath 600. As shown, the sheath600 includes a generally cylindrical body 608. The body 608 is generallyhollow, with a solid back wall 610 and a bore 614 extending through thebody 608 and terminating at the back wall 610. An indent 612 is formedin a top of the sheath 600, at a front of the body 608. In operation,the indent 612 may be aligned with a complementary indent 812 on theknob 800 to indicate a zero degree rotational angle of the knob 800 withrespect to the sheath 600. In some examples, some other indication(e.g., marking, texturing, coloring, etc.) may be used in place of theindent 612 and/or complementary indent 812.

In the examples of FIGS. 6B-6C, a protrusion 616 extends into the bore614 on a bottom of the sheath 600, opposite (or 180 degrees from) theindent 612 in the top. In some examples, the protrusion 616 may be abolt or other fastener inserted through an aperture formed in the bottomof the sheath 600. In the example of FIG. 6C, the protrusion 616 is theshank of a bolt, having a bolt head 617. In operation, the protrusion616 may be fitted within a passageway 816 of the knob 800 to facilitatelateral and/or rotational movement of the knob 800. In the example ofFIG. 7, the sheath 600 also includes attachment points 618 on the bottomof the sheath 600 facilitate attachment to the housing 102. In someexamples the attachment points 618 may comprise holes configured forreception of screws, bolts, and/or other fasteners.

FIGS. 7-8C show further details of the knob 800. As shown, knob 800includes a head 804 and a shaft 806. Both the head 804 and shaft 806 aregenerally cylindrical, with the head 804 having a larger diameter thanthe shaft 806. The diameter of the head 804 is larger than the diameterof the bore 614, such that the head 804 will not fit within the bore 614of the sheath 600. However, the diameter of the shaft 806 is smallenough to fit comfortably within the bore 614 of the sheath 600.

In the examples of FIGS. 7-8C, the shaft 806 includes the channel 802and a passageway 816. As shown, the passageway 816 is formed between thechannel 802 and the head 804 of the knob 800. The channel 802 is formedbetween the passageway 816 and an end 818 of the knob 800. As shown, thechannel 802 extends all the way around the shaft 806 of the knob 800,forming an annular trench. However, in the examples of FIGS. 7-8C, thepassageway 816 only extends over a portion of the shaft 806, whichlimits the potential movement of the knob 800 within the sheath 600. Thepassageway 816 is configured to slidably fit the protrusion 616 therein,such that the knob 800 can move over the protrusion 616 (and theprotrusion 616 can move within the passageway 816) when the knob 800 ismoved between the extended and retracted positions, and betweenrotational positions.

In the examples of FIGS. 7-8C, the passageway 816 includes a lateralportion 820 and an arcuate portion 822. As shown, the arcuate portion822 extends in an arc from the lateral portion 820 to a positionapproximately aligned with the complementary indent 812 of the knob 800.As shown, the lateral portion 820 extends approximately perpendicular tothe arcuate portion 822 and channel 802 of the dispensing knob 800, andapproximately parallel to the lateral slots 606.

In the examples of FIGS. 7-8C, the lateral portion 820 of the passageway816 intersects with the arcuate portion 822, which allows the protrusion616 to transition from one portion of the passageway 816 to another. Inoperation, the protrusion 616 moves within the lateral portion 820 whenthe knob 800 is moved between the extended and retracted positions. Theprotrusion 616 is farthest from the intersection of the lateral portion820 and arcuate portion 822 when the knob 800 is extended as far aspossible from the sheath 600 (e.g., such as shown in FIG. 5A). Thelength of the lateral portion 820 limits how far the knob 800 can extendaway from the sheath 600.

While in the extended position, the knob 800 can only move laterallybetween the extended and retracted positions, because the lateralportion 820 of the passageway 816 is the only path available for theprotrusion 616 to travel. When moving laterally, the complementaryindent 812 formed on the head 804 of the knob 800 is aligned with theindent 612 on the sheath 600. However, once in the retracted position(e.g., of FIG. 5B), the protrusion 616 will reach the intersectionbetween the lateral portion 820 and arcuate portion 822 of thepassageway 816, and thus be in a position to travel through the arcuateportion 822, allowing for rotational movement of the knob 800.

The knob 800 is configured for rotational movement within the sheath 600when in the retracted position (e.g., such as shown in FIG. 5C). Inoperation, the protrusion 616 moves within the arcuate portion 822 ofthe passageway 816 when the knob 800 rotates within the sheath 600. INthe example of FIG. 5C, when the protrusion 616 moves within the arcuateportion 822 of the passageway 816 out of alignment with the lateralportion 820, the complementary indent 812 formed on the head 804 of theknob 800 likewise moves out alignment with the indent 612 on the sheath600. Thus, an operator can see quickly how far the knob 800 has beenrotated, and/or if the knob 800 can be moved laterally.

In the examples of FIGS. 8A-8C, the channel 802 of the knob 800 has adepth D that varies depending on the rotational position of the knob800. As shown, the depth D of the channel 802 decreases as the knob 800is rotated. FIGS. 8A-8C show examples of the knob 800 at differentrotational positions, illustrating this decreasing variation. Inparticular, the examples of FIGS. 8A-8C show the depth D of the channel802 where the dispensing tube would be positioned (e.g., in alignmentwith the lateral slots 606 of the sheath 600). In the example of FIG.8A, the knob 800 has not been rotated (i.e., 0 degree rotation). Asshown, the depth D in FIG. 8A is relatively large. In the example ofFIG. 8B, the knob 800 has been rotated approximately forty-five degrees(i.e., some rotation). As shown, the depth D in FIG. 8B is less than inFIG. 8A. In the example of FIG. 8C, the knob 800 has been rotatedapproximately ninety degrees (i.e., full rotation). As shown, the depthD in FIG. 8C is less than in both FIGS. 8A and 8B.

The varying depth D of the channel 802 allows an operator to vary flowof epoxy through the dispensing tube by turning the knob 800 when in theretracted position. When the knob 600 is in the retracted position, thedispensing tube remains substantially aligned with the lateral slots 606of the sheath 600. However, the depth D of the channel 802 in alignmentwith the lateral slots 606 decreases as the knob 800 is rotated. Thus,while the dispensing tube fits comfortably within the channel 802 whenthe knob 800 is at 0 degrees of rotation (e.g., FIG. 5A), the dispensingtube begins to become pinched (e.g., between the shaft 806 defining thebottom of the channel 802 and the sheath 600) when the angle of rotationincreases. The more the knob 800 is turned, the smaller the depth D ofthe channel 802 gets, and the more the dispensing tube is pinched. Themore the dispensing tube is pinched, the more the flow of epoxy throughthe dispensing tube is restricted. Thus, an operator may adjust the flowof epoxy through the dispensing tube by changing the rotation of theknob 800 within the sheath 600.

As discussed above, however, the knob 800 may only be rotated after putinto the retracted position. Thus, an operator may prevent accidentalflow restriction by positioning the knob in the extended position.Additionally, while in the extended position, the window 602 allows forthe dispensing tube to be easily inserted and/or removed with minimaleffort and/or awkwardness.

While the present apparatus, systems, and/or methods have been describedwith reference to certain implementations, it will be understood bythose skilled in the art that various changes may be made andequivalents may be substituted without departing from the scope of thepresent apparatus, systems, and/or methods. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present disclosure without departing from itsscope. Therefore, it is intended that the present apparatus, systems,and/or methods not be limited to the particular implementationsdisclosed, but that the present apparatus, systems, and/or methods willinclude all implementations falling within the scope of the appendedclaims.

What is claimed is:
 1. A vacuum system for mounting of material samples,comprising: a flow control device, comprising: a sheath having a centralbore and a slot; and a dispensing knob received in the central bore ofthe sheath, the dispensing knob having a channel configured to receive adispensing tube, wherein the dispensing knob is configured to movelaterally between an extended position, where the channel is inalignment with the slot, and a retracted position, where the channel isout of alignment with the slot.
 2. The system of claim 1, wherein thechannel has a depth that varies based on a rotatable position of thedispensing knob.
 3. The system of claim 1, wherein the dispensing knobis further configured to move between a first rotatable position and asecond rotatable position when the dispensing knob is in the retractedposition.
 4. The system of claim 3, wherein the depth of the channelproximate the slot is less in the second rotatable position than in thefirst rotatable position, such that fluid flow through the dispensingtube is more restricted in the second rotatable position than in thefirst rotatable position.
 5. The system of claim 1, further comprising aprotrusion extending into the central bore, the protrusion beingreceived by a passageway of the dispensing knob.
 6. The system of claim5, wherein the passageway extends at least partially around a perimeterof the dispensing knob, thereby allowing the dispensing knob to rotatewithin the sheath.
 7. The system of claim 6, wherein the passagewaycomprises an arcuate portion extending at least partially around theperimeter of the dispensing knob and a lateral portion extendingperpendicular to the arcuate portion.
 8. The system of claim 7, whereinthe lateral portion of the passageway slides over the protrusion whenthe dispensing knob moves laterally between the extended position andthe retracted position.
 9. The system of claim 7, wherein the arcuateportion of the passageway slides over the protrusion when the dispensingknob moves between the first rotational position and the secondrotational position.
 10. The system of claim 3, wherein the dispensingknob is prohibited from moving between the first rotatable position andsecond rotatable position when the dispensing knob is in the extendedposition.
 11. A method of controlling fluid flow through a tube of avacuum system, the method comprising: positioning the tube in a channelof a dispensing knob while the dispensing knob is in an extendedposition, the dispensing knob being retained within a sheath, and thechannel being aligned with a slot of the sheath when the dispensing knobis in the extended position; moving the dispensing knob from theextended position to a retracted position where the channel is out ofalignment with the slot of the sheath; and rotating the dispensing knobwhile the dispensing knob is in the retracted position, wherein therotation causes the dispensing knob and sheath to pinch the tube. 12.The method of claim 11, wherein the channel has a depth that variesbased on a rotatable position of the dispensing knob.
 13. The method ofclaim 11, wherein rotating the dispensing knob comprises rotating thedispensing knob from a first rotatable position to a second rotatableposition.
 14. The method of claim 13, wherein the dispensing knob isprohibited from moving to the extended position from the retractedposition when the dispensing knob is in the second rotatable position.15. The method of claim 13, wherein the depth of the channel proximatethe slot is less in the second rotatable position than in the firstrotatable position, such that fluid flow through the tube is morerestricted in the second rotatable position than in the first rotatableposition.
 16. The method of claim 13, further comprising rotating thedispensing knob from the second rotatable position to a third rotatableposition.
 17. The method of claim 16, wherein the depth of the channelproximate the slot is less in the third rotatable position than in thesecond rotatable position, such that fluid flow through the tube is morerestricted in the third rotatable position than in the second rotatableposition.
 18. The method of claim 11, wherein a protrusion moves withina lateral passageway of the dispensing knob when moving the dispensingknob to the retracted position.
 19. The method of claim 18, wherein aprotrusion moves within an arcuate passageway of the dispensing knobwhen rotating the dispensing knob.
 20. The method of claim 11, furthercomprising routing the tube from a reservoir, through the channel of thedispensing knob, to a vacuum chamber of the vacuum system.